Comparison

SunDose! vs Zero

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

SunDose!

This app helps you establish a consistent morning sunlight habit to improve sleep, mood, and energy. It offers personalized goals, streak tracking, and educational content, with premium features for advanced health metrics and AI insights.

Highlights
  • Personalized daily sunlight goals
  • Streak tracking for consistency
  • Detailed progress visualization
  • Educational content on sunlight benefits
  • Reminders for habit maintenance
  • Vitamin D and sleep optimization tracking
Features
Read full description

Harness the Power of Morning Sunlight Sundose! makes it easy to build a consistent morning sunlight habit - one of the most powerful yet overlooked health practices. Just 10-30 minutes of morning sunlight can transform your sleep, mood, and energy levels. Benefits of Morning Sunlight: • Regulate your circadian rhythm for better sleep • Boost your mood and energy levels • Improve focus and mental clarity • Support vitamin D production • Enhance overall well-being Key Features: • Simple, beautiful sunlight tracking • Personalized daily goals based on your location • Streak tracking to build consistency • Detailed statistics and progress visualization • Educational content on sunlight benefits • Reminders to help maintain your habit Premium Features: • Key Health Metrics: Track Vitamin D Score, Sleep Optimization, and Consistency • Personalized Daily Plan: Optimal morning & evening light windows with weather & UV info • AI-Powered Insights: Custom analysis and tips based on your sunlight patterns Based on Science: Sundose! incorporates research on circadian biology and sunlight exposure to help you optimize your daily routine for better health outcomes. Download Sundose! today and make morning sunlight a cornerstone of your wellness routine! Privacy Focused: Your health data stays private. Location data is only used to provide accurate sunlight recommendations. Terms of Use (EULA) URL: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy URL: https://www.privacypolicies.com/live/55054f53-fa7c-4f19-bb6d-f407d8c04c83

About

Zero

This app helps you manage stress by combining guided breathing exercises with real-time biometric data from your Apple Watch. It provides insights into your stress patterns and helps you schedule recovery moments to build resilience.

Highlights
  • Guided breathing exercises
  • Real-time biometric tracking (RHR, HRV)
  • Stress pattern analysis
  • Scheduled mindful breaks
  • Relaxation validation
  • Local data storage
Features
Read full description

Zero Rush — Your Relaxation Tracker Zero Rush helps you slow down, reset, and understand your stress. Combining guided breathing, real-time biometrics, and relaxation tracking, it gives you measurable insights into how your body responds to stress — so you can take control, not just calm down. Relaxation Tracker Discover what really helps you relax — massage, meditation, music, or silence. Track how your heart rate changes before and after each session to validate what actually works for you. Track Your Stress & Understand Your Patterns With Apple Watch, Zero Rush calculates your stress level using your latest Resting Heart Rate (RHR) and Heart Rate Variability (HRV). See when your stress increases, identify your triggers, and understand your patterns by time of day and day of the week. Breathe Better Use scientifically backed breathing methods like 4-7-8 or Box Breathing to reduce tension and improve focus. Customize your own breathing method and create the perfect rhythm for your daily breaks. Scheduled Breaks Plan your daily recovery moments. Set up smart reminders to take mindful breaks throughout the day, and reconnect with yourself for just a few minutes at a time. Privacy by Design Your data never leaves your device. Everything is stored locally and visible only to you. Zero Rush is not a medical device and does not provide diagnosis or treatment. It is intended for wellness and educational purposes only. Compatible with: iPhone & Apple Watch. Apple Watch unlocks live HRV, resting heart rate, and real-time stress tracking — Zero Rush also works without one. Stop guessing what calms you. Start knowing. Terms of Use: https://www.zero-rush.com/terms-of-use/ Privacy Policy: https://www.zero-rush.com/privacy-policy/ EULA: https://www.zero-rush.com/eula/

Screenshots

SunDose!4 screens
Zero4 screens

Verdict

The call

The clearest difference is update cadence: SunDose! at every 4 days against Zero's every 3 weeks. SunDose! also leads on ratings volume (4 vs 1) and iOS requirement (15.1 vs 18.5). On price, rating, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. SunDose! sells 3 in-app purchases, starting at $2.99 per month and Zero sells 3 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for SunDose! against 5.0 for Zero. Both are backed by a comparable volume of ratings — 4 and 1 respectively.

UpkeepUpdate frequency

SunDose! ships an update every 4 days, Zero every 3 weeks. The most recent releases landed on October 7, 2026 and October 16, 2026 respectively.

Scorecard3 real differences · 7 level
SunDose! versus Zero: the parameters behind the verdict, then further details
ParameterSunDose!Zero
PriceFreeFree
Rating5.0 (4 ratings)5.0 (1 ratings)
Positive reviews100.0% of reviews—
Number of ratings4 — better1
Update frequencyEvery 4 days — betterEvery 3 weeks
AdsNoNo
In-app purchasesYesYes
MonetizationFreemiumFreemium
DevicesiPhone, iPad, iPod — betteriPhone, Apple Watch
Requires iOS15.1 — better18.5
Further details — not scored
Size37 MB10 MB
Age rating17+4+
DeveloperPrispa Solutions LLCCarlos Adiel Vega Lopez

Customer experience

SunDose!

All ratings4 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews3 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Zero

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

3 purchases

SunDose!

Subscriptions2
  • Unlimited access7 Days trial$2.991 Month
  • Unlimited access7 Days trial$29.991 Year
One-time1
  • Unlimited access$69.99
3 purchases

Zero

Subscriptions2
  • All Access – Monthly14 Days trial$1.991 Month
  • All Access – Yearly14 Days trial$19.991 Year
One-time1
  • Lifetime All Access$89.99

Questions

Is SunDose! free?
SunDose! is free to download, with in-app purchases available.
Is Zero free?
Zero is free to download, with in-app purchases available.
Which has better reviews, SunDose! or Zero?
SunDose! and Zero are both rated 5.0 out of 5 on the App Store, from 4 and 1 ratings respectively.
Do SunDose! or Zero have ads?
Neither SunDose! nor Zero shows ads.
Which is updated more often, SunDose! or Zero?
SunDose! ships an update every 4 days, and Zero every 3 weeks. Most recently, SunDose! was updated on October 7, 2026 and Zero on October 16, 2026.

Other comparisons